Old school wiring is one way to get it working,and probably the quickest. I don't think the a/c is fed thru the pcm or ecm on a 24v, but let me verify this and I'll post the correct answer.

I clean the a/c system with charcoal starting fluid. It gets the crap out. Then I use alcohol to get the oils out. When you convert to R134, use 15% to 20% less than R12. Ice cold air every time.
Change the accumulator and orifice after cleaning system.

i converted mine to R290. (They're All Gonna Laugh at me! Nooo...) this thing blows colder then any A/C i have ever seen, blows ice cold fog out of the vents. passengers ask me to turn it off within a few minutes of turning it on its so cold.

it works with all of the A/C oils. the most trouble i had doing it was balancing the system as the high side was near the pressure release valves setting. but once done it was a dream

cheap too. also non ozone depleting.

no it wont blow up, use safe work practices as any mechanic should and you'll be fine. people have been barbecuing on this stuff for generations. anyone who has the skill to retrofit an A/C system should be able figure this out.

be safe

Jason